Punch



Patented Nov. 8, 1932 12 UNITED STATES P TENTQFF E JOHN C. OLSEN, OF CHICAGO, ILLINOIS,

AssIGNoR T FLEXIBLE. srnnn IlAoINo: f

COMPANY, 01 CHICAGO, ILLINOIS, A CORPORATION or. ILLINOIS 'ruirn I Application filed April 17,

This invention relates to improvements in punches and more particularly punches adapted for making holes in belts of leather,

canvas and the like to permit application of' belt fasteners thereto.

One object of the invention is to provide an eificient, rugged and durable punch of economical construction for punching holes in articles such as belts and the like.

Specific objects of the invention are to provide a hollow punch of the character above indicated and having a wavy or fluted edge easy to force through the material operated upon and wherein the cutting edge is easily maintained in sharp condition, the construction being further characterized by the fact that any tendency of the punch to shift out of line as it is forced through the material is minimized or entirely eliminated.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the drawing forming a part of this specification, Figure 1 is a perspective view of a hand punch embodying my improvements, said figure being substantially full size. Figures 2 and 3 are transverse, sectiona1 views corresponding to the lines 22 and" 33, respectively, of Figure 1 upon enlarged 3o scales. And Figures 4 and 5 are longitudinal, diametrical, sectional views corresponding substantially to the lines 4-4 and 55 respectively, of Figure -2.

The improved punch, as shown, comprises a solid top or head end 10, an intermediate open sided section 11 and a hollow tubular terminus or active punching end 12. All pors tions are of circular cross section, the head or striking end being preferably beveled, as

140 indicatedat 13 and, for convenience in exother article operated upon.

pointed projectioiis are formed. f-

E' The intermediate section 11 is provided with an elongated opening 15 along one side thereof, which serves as' an ejector opening for the punchings'that'are pushed up through the active end of the punch, as will be understoo'dL- h r The lower tubular terminal section 12 is of reduced-ekternal diameter-, as compared with the intermediate andlhead sections, the intermediate and terminal section 12 being uni-ted '55 by a tapered portion 16,-as shown. The ten minal section 12 has'an interior opening '17 commu'nicatingwith the discharge or ejector opening '15,,said terminal portion being of uniform inside and outside diameter-throughout its entire length and preferably, on account of the materials on which itisintended to be used, the thickness or crosssection of the wall of the "terminal section 12 will be maintained not less" than ".015 inches and not greater than 0.50 inches by reason of which the punch will not collapse, yet at the same "time will permit of easy passageofthe punch through the material." I- have found that a "satisfactory thickness I is approxi1nately .03 "70 "inches; f Y -'-The lower cutting edge of the section 12 is of special formation having, as shown, two diametrically disposed portions] 1818,

which are longitudinally "in advance of the 75 intervening edge portions l919, the edge 'consistingof what may be termedapproxi- *matelyogee curves, as viewed in side eleva- 'tion. The cutting edge is also'beveled downwardly and inwardly toward the'aXis of the punch, as indicated at20, around'the'entirei circumference, said bevel being maintained Within the limits of 25'-'and angleswith "reference to the axis. 1' have foundthat a' bevel of approximately 45 is" satisfactory ,85

and maybe easily maintained. As will be evident from" the drawing, the curves of the j ogeeformation are relatively shallow or of short amplitude, "so that no sharp "or narrow By making the terminal punching portion 12 of uniform cross section and diameter, and of a length substantially in excess of the thiclmess of the material to be punched, and by having circumferentially spaced portions as 18-18 of the cutting edge in advance of the intervening portions, I have found that the punch will pass readily through any ordinary thickness of belting without danger of crushing or distorting the punch and with a clean cut hole. By having portions of the cutting edge as 18-18 in advance of the in tervening portions, the portions 18 obviously initially engage themateri-al, start the. cut

at two circumferentially spaced points, the remainder of the cut for the punching being 7 obtained by a progressive circular shearing April, 1931 JOHN G. OLSEN.

effect. Furthermore, bymaking the number a,

of advanced cutting portions 18 an even num' ber, the cutting action is balanced so as to' prevent tendency of the punch to be shifted laterally in its passage through the material. With a punch constructed as hereinabove described, the cutting edge may be easily maintained sharp by suitable grinding at in? tervals; the punch may be manufactured at relatively small cost and is of rugged con- .struction, assuring long life.

Although I have herein; shown and described what I nowconsider the preferred manner of carrying out my invention, the

same is merely illustrative and I contemplate all changes and modificationsthat come with in the scope of the claims appended hereto.

I claim: g V

1. A punch having a, solid head, an intermediate hollow section with a lateral discharge opening for thepunchings, and a hollow tubular terminal section of uniform cross section throughout and of lesser external di- I ameter than that of the intermediate section,

[said terminal section having anactive cutting edge beveledin longitudinal section, said I edge being formed with a plurality of uniformly, circumferentially spaced portions thereof disposed longitudinally in advance of the intervening portions, said cutting edge,

in elevation, presentinga plurality of substantially ogee curves.

2. A punch for leather, canvas and similar materials comprising: a head and intermediate hollow section; and a terminal hollow vtubular section, said terminal section being of uniform size and cross section throughout and provided with an active cutting edge beveled in longitudinal section, said edge being .7

so formed as to present a plurality of substantially uniformly 'circumferentially disposed ogee curves, as viewed in side elevation.

3. A punch in accordance with claim 2 wherein said ogee curves are relatively shal w low and the thickness of said tubular terminal section is between the minimum and maximum limits of .015 and'.050 inches,

1. A punch in accordance with claim 2 

